Hello!
Firstly I am sure there'll be other posters along, I'm a nightbird myself occasionally, not up with a baby these days. I hope you get some answers and reassurance.
Secondly your baby sounds settled and contented, great job! I do know others love to stick their oar in unasked and offer advice whether you ask for it or not... but don't let it get you down. Is it a recent thing, this dent in confidence?
My children are pretty well grown now 1 late teens and 1 is 20 so my knowledge is rusty I'm afraid, but please don't let anyone else make you feel inadequate or somehow not sticking to unwritten rules. Others often mean well, some are just letting the world know how great they are.
You raised one son I am sure you are coping fine with your 2nd!
I hardly knew one end of a baby from another when I had my son. Admittedly I was married so was able to rely on some support and we were a kind of tag team. My mum lived very locally but owing to some unfortunate misunderstanding pre birth I never de-coded she didn't ever help out. We got by.
As well as advice on different topics on Mumsnet I have seen mention of 2 Mumsnet books, 1 about Pregnancy, 1 about Babies. Anyway it does look possible to wade through many past posts on many threads so if you can access MN online there must be lots on weaning and sleep...
Routines ie chunks of day or night organised (in my case, after certain feeding and sleep patterns evolved) are meant to help structure your life, not dominate. I considered it a routine just getting myself up, starting the cycle of cuddles, feed, change, wash, dress, housework and somewhere get myself fit to be seen. Some would say it's flexibility that serves you best.
Have babbled on but wanted to say what works for you & your baby is good enough, if your HV had any concerns she would have raised them. We all need a helping hand or advice from time to time, let off steam here.